First Author:   Valentine Soumtang Bime University of Yaounde II valentinebime@yahoo.com   University of Yaounde II, Faculty and Economics and Management Yaounde, 1365, Cameroun   00237697182014(Phone) 00237697182014(Fax) Second Author: Itchoko Motande Mondjeli Mwa Ndjokou University of Maroua motande@yahoo.fr   Faculty and Economics and Management, Faculty and Economics and Management Maroua